/**
 * @param {string} s
 * @param {string} t
 * @return {number}
 */
 var minSteps = function(s, t) {
  const mp1 = new Map(), mp2 = new Map()
  for(let ch of s) {
    mp1.set(ch, (mp1.get(ch) ?? 0) + 1)
  }
  for(let ch of t) {
    mp2.set(ch, (mp2.get(ch) ?? 0) + 1)
  }
  let ans = 0
  let used = new Set()
  for(let [k, v] of mp1) {
    used.add(k)
    if(!mp2.has(k)) {
      ans += v
      continue
    }
    let x = mp2.get(k)
    if(x !== v) {
      ans += Math.abs(x-v)
    }
  }
  for(let [k, v] of mp2) {
    if(!used.has(k)) {
      ans += v
    }
  }
  return ans
};